The invention relates to concurrently copying both sides of an original, and specifically to copying both sides of an original sheet onto photographic film.
There is a prior art rotary camera for simultaneously photographing both sides of a document on a film, and there is a prior art machine for simultaneously copying both sides of a document onto a copy sheet. In such prior art devices the two sides of the original are illuminated by incident beams through shielding plates having aligned windows and the reflected light is projected onto a film or onto a copy sheet. One disadvantage with such prior art devices is that since the same part of the original is illuminated from both sides, some light is transmitted through the original to form a shadow, and each reflected beam contains both a reflected image and a transmitted shadow. Therefore, particularly where the original is somewhat transparent, a faint copy of the wrong side of the original is superimposed on the copy of the proper side of the original.